Including debt, it values Thomson Reuters’ Financial & Risk business at $US20 billion, making it the largest deal Blackstone has arranged since the financial crisis.

Guiding Blackstone on the mammoth deal was a tiny investment bank out of the United Kingdom that has been around for less than a year.

Canson Capital Partners, a boutique advisory firm founded in early 2017 by ex-HSBC bankers James Simpson and Matteo Canonaco, had a lead role advising Blackstone, which will net the firm a healthy chunk of the $US10 million to $US20 million in fees Blackstone is expected to pay its bankers, according to Jeffrey Nassof, the director of consulting firm Freeman & Co. Bank of America Merrill Lynch, Citigroup, and JPMorgan also advised Blackstone.

Canson, formerly named DuCanon, is an outfit of just three bankers and two senior advisers based out of a Mayfair office building in London, where it focuses on private equity transactions.

“Very proud to announce Canson Capital Partners Lead Advisory role in Blackstone’s Partnership with Thomson Reuters,” Simpson wrote on LinkedIn.

It’s not their first time advising Blackstone, the world’s largest private equity firm. The boutique’s inaugural deal came last July, four months after launching, when it helped Blackstone buy Clarion Events for £600 million ($US850 million), according to the Financial Times.

Guggenheim Securities was the lead adviser to Thomson Reuters. It will split a fee of $US50 million to $US60 million, according to Nassof, with TD Securities and Centerview Partners, a small advisory boutique that had a stellar year in advising on megadeals in 2017.

Still, at 37 partners, Centerview almost looks like a bulge bracket bank compared with the three partners at Canson.

In total, the banks could earn as much as $US80 million for advising on the transaction.

The deal is expected to be financed with $US13 billion in debt, which Bank of America Merrill Lynch, Citigroup, and JPMorgan will split $US130 million to $US160 million in fees for arranging, according to Nassof